net/can/raw.c

   1 /*
   2  * raw.c - Raw sockets for protocol family CAN
   3  *
   4  * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of Volkswagen nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * Alternatively, provided that this notice is retained in full, this
  20  * software may be distributed under the terms of the GNU General
  21  * Public License ("GPL") version 2, in which case the provisions of the
  22  * GPL apply INSTEAD OF those given above.
  23  *
  24  * The provided data structures and external interfaces from this code
  25  * are not restricted to be used by modules with a GPL compatible license.
  26  *
  27  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  28  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  29  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  30  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  31  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  32  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  33  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  34  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  35  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  36  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  37  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
  38  * DAMAGE.
  39  *
  40  */
  41
  42 #include <linux/module.h>
  43 #include <linux/init.h>
  44 #include <linux/uio.h>
  45 #include <linux/net.h>
  46 #include <linux/slab.h>
  47 #include <linux/netdevice.h>
  48 #include <linux/socket.h>
  49 #include <linux/if_arp.h>
  50 #include <linux/skbuff.h>
  51 #include <linux/can.h>
  52 #include <linux/can/core.h>
  53 #include <linux/can/skb.h>
  54 #include <linux/can/raw.h>
  55 #include <net/sock.h>
  56 #include <net/net_namespace.h>
  57
  58 #define CAN_RAW_VERSION CAN_VERSION
  59
  60 MODULE_DESCRIPTION("PF_CAN raw protocol");
  61 MODULE_LICENSE("Dual BSD/GPL");
  62 MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>");
  63 MODULE_ALIAS("can-proto-1");
  64
  65 #define MASK_ALL 0
  66
  67 /*
  68  * A raw socket has a list of can_filters attached to it, each receiving
  69  * the CAN frames matching that filter.  If the filter list is empty,
  70  * no CAN frames will be received by the socket.  The default after
  71  * opening the socket, is to have one filter which receives all frames.
  72  * The filter list is allocated dynamically with the exception of the
  73  * list containing only one item.  This common case is optimized by
  74  * storing the single filter in dfilter, to avoid using dynamic memory.
  75  */
  76
  77 struct uniqframe {
  78         int skbcnt;
  79         const struct sk_buff *skb;
  80         unsigned int join_rx_count;
  81 };
  82
  83 struct raw_sock {
  84         struct sock sk;
  85         int bound;
  86         int ifindex;
  87         struct notifier_block notifier;
  88         int loopback;
  89         int recv_own_msgs;
  90         int fd_frames;
  91         int join_filters;
  92         int count;                 /* number of active filters */
  93         struct can_filter dfilter; /* default/single filter */
  94         struct can_filter *filter; /* pointer to filter(s) */
  95         can_err_mask_t err_mask;
  96         struct uniqframe __percpu *uniq;
  97 };
  98
  99 /*
 100  * Return pointer to store the extra msg flags for raw_recvmsg().
 101  * We use the space of one unsigned int beyond the 'struct sockaddr_can'
 102  * in skb->cb.
 103  */
 104 static inline unsigned int *raw_flags(struct sk_buff *skb)
 105 {
 106         sock_skb_cb_check_size(sizeof(struct sockaddr_can) +
 107                                sizeof(unsigned int));
 108
 109         /* return pointer after struct sockaddr_can */
 110         return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]);
 111 }
 112
 113 static inline struct raw_sock *raw_sk(const struct sock *sk)
 114 {
 115         return (struct raw_sock *)sk;
 116 }
 117
 118 static void raw_rcv(struct sk_buff *oskb, void *data)
 119 {
 120         struct sock *sk = (struct sock *)data;
 121         struct raw_sock *ro = raw_sk(sk);
 122         struct sockaddr_can *addr;
 123         struct sk_buff *skb;
 124         unsigned int *pflags;
 125
 126         /* check the received tx sock reference */
 127         if (!ro->recv_own_msgs && oskb->sk == sk)
 128                 return;
 129
 130         /* do not pass non-CAN2.0 frames to a legacy socket */
 131         if (!ro->fd_frames && oskb->len != CAN_MTU)
 132                 return;
 133
 134         /* eliminate multiple filter matches for the same skb */
 135         if (this_cpu_ptr(ro->uniq)->skb == oskb &&
 136             this_cpu_ptr(ro->uniq)->skbcnt == can_skb_prv(oskb)->skbcnt) {
 137                 if (ro->join_filters) {
 138                         this_cpu_inc(ro->uniq->join_rx_count);
 139                         /* drop frame until all enabled filters matched */
 140                         if (this_cpu_ptr(ro->uniq)->join_rx_count < ro->count)
 141                                 return;
 142                 } else {
 143                         return;
 144                 }
 145         } else {
 146                 this_cpu_ptr(ro->uniq)->skb = oskb;
 147                 this_cpu_ptr(ro->uniq)->skbcnt = can_skb_prv(oskb)->skbcnt;
 148                 this_cpu_ptr(ro->uniq)->join_rx_count = 1;
 149                 /* drop first frame to check all enabled filters? */
 150                 if (ro->join_filters && ro->count > 1)
 151                         return;
 152         }
 153
 154         /* clone the given skb to be able to enqueue it into the rcv queue */
 155         skb = skb_clone(oskb, GFP_ATOMIC);
 156         if (!skb)
 157                 return;
 158
 159         /*
 160          *  Put the datagram to the queue so that raw_recvmsg() can
 161          *  get it from there.  We need to pass the interface index to
 162          *  raw_recvmsg().  We pass a whole struct sockaddr_can in skb->cb
 163          *  containing the interface index.
 164          */
 165
 166         sock_skb_cb_check_size(sizeof(struct sockaddr_can));
 167         addr = (struct sockaddr_can *)skb->cb;
 168         memset(addr, 0, sizeof(*addr));
 169         addr->can_family  = AF_CAN;
 170         addr->can_ifindex = skb->dev->ifindex;
 171
 172         /* add CAN specific message flags for raw_recvmsg() */
 173         pflags = raw_flags(skb);
 174         *pflags = 0;
 175         if (oskb->sk)
 176                 *pflags |= MSG_DONTROUTE;
 177         if (oskb->sk == sk)
 178                 *pflags |= MSG_CONFIRM;
 179
 180         if (sock_queue_rcv_skb(sk, skb) < 0)
 181                 kfree_skb(skb);
 182 }
 183
 184 static int raw_enable_filters(struct net *net, struct net_device *dev,
 185                               struct sock *sk, struct can_filter *filter,
 186                               int count)
 187 {
 188         int err = 0;
 189         int i;
 190
 191         for (i = 0; i < count; i++) {
 192                 err = can_rx_register(net, dev, filter[i].can_id,
 193                                       filter[i].can_mask,
 194                                       raw_rcv, sk, "raw", sk);
 195                 if (err) {
 196                         /* clean up successfully registered filters */
 197                         while (--i >= 0)
 198                                 can_rx_unregister(net, dev, filter[i].can_id,
 199                                                   filter[i].can_mask,
 200                                                   raw_rcv, sk);
 201                         break;
 202                 }
 203         }
 204
 205         return err;
 206 }
 207
 208 static int raw_enable_errfilter(struct net *net, struct net_device *dev,
 209                                 struct sock *sk, can_err_mask_t err_mask)
 210 {
 211         int err = 0;
 212
 213         if (err_mask)
 214                 err = can_rx_register(net, dev, 0, err_mask | CAN_ERR_FLAG,
 215                                       raw_rcv, sk, "raw", sk);
 216
 217         return err;
 218 }
 219
 220 static void raw_disable_filters(struct net *net, struct net_device *dev,
 221                                 struct sock *sk, struct can_filter *filter,
 222                                 int count)
 223 {
 224         int i;
 225
 226         for (i = 0; i < count; i++)
 227                 can_rx_unregister(net, dev, filter[i].can_id,
 228                                   filter[i].can_mask, raw_rcv, sk);
 229 }
 230
 231 static inline void raw_disable_errfilter(struct net *net,
 232                                          struct net_device *dev,
 233                                          struct sock *sk,
 234                                          can_err_mask_t err_mask)
 235
 236 {
 237         if (err_mask)
 238                 can_rx_unregister(net, dev, 0, err_mask | CAN_ERR_FLAG,
 239                                   raw_rcv, sk);
 240 }
 241
 242 static inline void raw_disable_allfilters(struct net *net,
 243                                           struct net_device *dev,
 244                                           struct sock *sk)
 245 {
 246         struct raw_sock *ro = raw_sk(sk);
 247
 248         raw_disable_filters(net, dev, sk, ro->filter, ro->count);
 249         raw_disable_errfilter(net, dev, sk, ro->err_mask);
 250 }
 251
 252 static int raw_enable_allfilters(struct net *net, struct net_device *dev,
 253                                  struct sock *sk)
 254 {
 255         struct raw_sock *ro = raw_sk(sk);
 256         int err;
 257
 258         err = raw_enable_filters(net, dev, sk, ro->filter, ro->count);
 259         if (!err) {
 260                 err = raw_enable_errfilter(net, dev, sk, ro->err_mask);
 261                 if (err)
 262                         raw_disable_filters(net, dev, sk, ro->filter,
 263                                             ro->count);
 264         }
 265
 266         return err;
 267 }
 268
 269 static int raw_notifier(struct notifier_block *nb,
 270                         unsigned long msg, void *ptr)
 271 {
 272         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 273         struct raw_sock *ro = container_of(nb, struct raw_sock, notifier);
 274         struct sock *sk = &ro->sk;
 275
 276         if (!net_eq(dev_net(dev), sock_net(sk)))
 277                 return NOTIFY_DONE;
 278
 279         if (dev->type != ARPHRD_CAN)
 280                 return NOTIFY_DONE;
 281
 282         if (ro->ifindex != dev->ifindex)
 283                 return NOTIFY_DONE;
 284
 285         switch (msg) {
 286
 287         case NETDEV_UNREGISTER:
 288                 lock_sock(sk);
 289                 /* remove current filters & unregister */
 290                 if (ro->bound)
 291                         raw_disable_allfilters(dev_net(dev), dev, sk);
 292
 293                 if (ro->count > 1)
 294                         kfree(ro->filter);
 295
 296                 ro->ifindex = 0;
 297                 ro->bound   = 0;
 298                 ro->count   = 0;
 299                 release_sock(sk);
 300
 301                 sk->sk_err = ENODEV;
 302                 if (!sock_flag(sk, SOCK_DEAD))
 303                         sk->sk_error_report(sk);
 304                 break;
 305
 306         case NETDEV_DOWN:
 307                 sk->sk_err = ENETDOWN;
 308                 if (!sock_flag(sk, SOCK_DEAD))
 309                         sk->sk_error_report(sk);
 310                 break;
 311         }
 312
 313         return NOTIFY_DONE;
 314 }
 315
 316 static int raw_init(struct sock *sk)
 317 {
 318         struct raw_sock *ro = raw_sk(sk);
 319
 320         ro->bound            = 0;
 321         ro->ifindex          = 0;
 322
 323         /* set default filter to single entry dfilter */
 324         ro->dfilter.can_id   = 0;
 325         ro->dfilter.can_mask = MASK_ALL;
 326         ro->filter           = &ro->dfilter;
 327         ro->count            = 1;
 328
 329         /* set default loopback behaviour */
 330         ro->loopback         = 1;
 331         ro->recv_own_msgs    = 0;
 332         ro->fd_frames        = 0;
 333         ro->join_filters     = 0;
 334
 335         /* alloc_percpu provides zero'ed memory */
 336         ro->uniq = alloc_percpu(struct uniqframe);
 337         if (unlikely(!ro->uniq))
 338                 return -ENOMEM;
 339
 340         /* set notifier */
 341         ro->notifier.notifier_call = raw_notifier;
 342
 343         register_netdevice_notifier(&ro->notifier);
 344
 345         return 0;
 346 }
 347
 348 static int raw_release(struct socket *sock)
 349 {
 350         struct sock *sk = sock->sk;
 351         struct raw_sock *ro;
 352
 353         if (!sk)
 354                 return 0;
 355
 356         ro = raw_sk(sk);
 357
 358         unregister_netdevice_notifier(&ro->notifier);
 359
 360         lock_sock(sk);
 361
 362         /* remove current filters & unregister */
 363         if (ro->bound) {
 364                 if (ro->ifindex) {
 365                         struct net_device *dev;
 366
 367                         dev = dev_get_by_index(sock_net(sk), ro->ifindex);
 368                         if (dev) {
 369                                 raw_disable_allfilters(dev_net(dev), dev, sk);
 370                                 dev_put(dev);
 371                         }
 372                 } else
 373                         raw_disable_allfilters(sock_net(sk), NULL, sk);
 374         }
 375
 376         if (ro->count > 1)
 377                 kfree(ro->filter);
 378
 379         ro->ifindex = 0;
 380         ro->bound   = 0;
 381         ro->count   = 0;
 382         free_percpu(ro->uniq);
 383
 384         sock_orphan(sk);
 385         sock->sk = NULL;
 386
 387         release_sock(sk);
 388         sock_put(sk);
 389
 390         return 0;
 391 }
 392
 393 static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
 394 {
 395         struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
 396         struct sock *sk = sock->sk;
 397         struct raw_sock *ro = raw_sk(sk);
 398         int ifindex;
 399         int err = 0;
 400         int notify_enetdown = 0;
 401
 402         if (len < sizeof(*addr))
 403                 return -EINVAL;
 404         if (addr->can_family != AF_CAN)
 405                 return -EINVAL;
 406
 407         lock_sock(sk);
 408
 409         if (ro->bound && addr->can_ifindex == ro->ifindex)
 410                 goto out;
 411
 412         if (addr->can_ifindex) {
 413                 struct net_device *dev;
 414
 415                 dev = dev_get_by_index(sock_net(sk), addr->can_ifindex);
 416                 if (!dev) {
 417                         err = -ENODEV;
 418                         goto out;
 419                 }
 420                 if (dev->type != ARPHRD_CAN) {
 421                         dev_put(dev);
 422                         err = -ENODEV;
 423                         goto out;
 424                 }
 425                 if (!(dev->flags & IFF_UP))
 426                         notify_enetdown = 1;
 427
 428                 ifindex = dev->ifindex;
 429
 430                 /* filters set by default/setsockopt */
 431                 err = raw_enable_allfilters(sock_net(sk), dev, sk);
 432                 dev_put(dev);
 433         } else {
 434                 ifindex = 0;
 435
 436                 /* filters set by default/setsockopt */
 437                 err = raw_enable_allfilters(sock_net(sk), NULL, sk);
 438         }
 439
 440         if (!err) {
 441                 if (ro->bound) {
 442                         /* unregister old filters */
 443                         if (ro->ifindex) {
 444                                 struct net_device *dev;
 445
 446                                 dev = dev_get_by_index(sock_net(sk),
 447                                                        ro->ifindex);
 448                                 if (dev) {
 449                                         raw_disable_allfilters(dev_net(dev),
 450                                                                dev, sk);
 451                                         dev_put(dev);
 452                                 }
 453                         } else
 454                                 raw_disable_allfilters(sock_net(sk), NULL, sk);
 455                 }
 456                 ro->ifindex = ifindex;
 457                 ro->bound = 1;
 458         }
 459
 460  out:
 461         release_sock(sk);
 462
 463         if (notify_enetdown) {
 464                 sk->sk_err = ENETDOWN;
 465                 if (!sock_flag(sk, SOCK_DEAD))
 466                         sk->sk_error_report(sk);
 467         }
 468
 469         return err;
 470 }
 471
 472 static int raw_getname(struct socket *sock, struct sockaddr *uaddr,
 473                        int *len, int peer)
 474 {
 475         struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
 476         struct sock *sk = sock->sk;
 477         struct raw_sock *ro = raw_sk(sk);
 478
 479         if (peer)
 480                 return -EOPNOTSUPP;
 481
 482         memset(addr, 0, sizeof(*addr));
 483         addr->can_family  = AF_CAN;
 484         addr->can_ifindex = ro->ifindex;
 485
 486         *len = sizeof(*addr);
 487
 488         return 0;
 489 }
 490
 491 static int raw_setsockopt(struct socket *sock, int level, int optname,
 492                           char __user *optval, unsigned int optlen)
 493 {
 494         struct sock *sk = sock->sk;
 495         struct raw_sock *ro = raw_sk(sk);
 496         struct can_filter *filter = NULL;  /* dyn. alloc'ed filters */
 497         struct can_filter sfilter;         /* single filter */
 498         struct net_device *dev = NULL;
 499         can_err_mask_t err_mask = 0;
 500         int count = 0;
 501         int err = 0;
 502
 503         if (level != SOL_CAN_RAW)
 504                 return -EINVAL;
 505
 506         switch (optname) {
 507
 508         case CAN_RAW_FILTER:
 509                 if (optlen % sizeof(struct can_filter) != 0)
 510                         return -EINVAL;
 511
 512                 if (optlen > CAN_RAW_FILTER_MAX * sizeof(struct can_filter))
 513                         return -EINVAL;
 514
 515                 count = optlen / sizeof(struct can_filter);
 516
 517                 if (count > 1) {
 518                         /* filter does not fit into dfilter => alloc space */
 519                         filter = memdup_user(optval, optlen);
 520                         if (IS_ERR(filter))
 521                                 return PTR_ERR(filter);
 522                 } else if (count == 1) {
 523                         if (copy_from_user(&sfilter, optval, sizeof(sfilter)))
 524                                 return -EFAULT;
 525                 }
 526
 527                 lock_sock(sk);
 528
 529                 if (ro->bound && ro->ifindex)
 530                         dev = dev_get_by_index(sock_net(sk), ro->ifindex);
 531
 532                 if (ro->bound) {
 533                         /* (try to) register the new filters */
 534                         if (count == 1)
 535                                 err = raw_enable_filters(sock_net(sk), dev, sk,
 536                                                          &sfilter, 1);
 537                         else
 538                                 err = raw_enable_filters(sock_net(sk), dev, sk,
 539                                                          filter, count);
 540                         if (err) {
 541                                 if (count > 1)
 542                                         kfree(filter);
 543                                 goto out_fil;
 544                         }
 545
 546                         /* remove old filter registrations */
 547                         raw_disable_filters(sock_net(sk), dev, sk, ro->filter,
 548                                             ro->count);
 549                 }
 550
 551                 /* remove old filter space */
 552                 if (ro->count > 1)
 553                         kfree(ro->filter);
 554
 555                 /* link new filters to the socket */
 556                 if (count == 1) {
 557                         /* copy filter data for single filter */
 558                         ro->dfilter = sfilter;
 559                         filter = &ro->dfilter;
 560                 }
 561                 ro->filter = filter;
 562                 ro->count  = count;
 563
 564  out_fil:
 565                 if (dev)
 566                         dev_put(dev);
 567
 568                 release_sock(sk);
 569
 570                 break;
 571
 572         case CAN_RAW_ERR_FILTER:
 573                 if (optlen != sizeof(err_mask))
 574                         return -EINVAL;
 575
 576                 if (copy_from_user(&err_mask, optval, optlen))
 577                         return -EFAULT;
 578
 579                 err_mask &= CAN_ERR_MASK;
 580
 581                 lock_sock(sk);
 582
 583                 if (ro->bound && ro->ifindex)
 584                         dev = dev_get_by_index(sock_net(sk), ro->ifindex);
 585
 586                 /* remove current error mask */
 587                 if (ro->bound) {
 588                         /* (try to) register the new err_mask */
 589                         err = raw_enable_errfilter(sock_net(sk), dev, sk,
 590                                                    err_mask);
 591
 592                         if (err)
 593                                 goto out_err;
 594
 595                         /* remove old err_mask registration */
 596                         raw_disable_errfilter(sock_net(sk), dev, sk,
 597                                               ro->err_mask);
 598                 }
 599
 600                 /* link new err_mask to the socket */
 601                 ro->err_mask = err_mask;
 602
 603  out_err:
 604                 if (dev)
 605                         dev_put(dev);
 606
 607                 release_sock(sk);
 608
 609                 break;
 610
 611         case CAN_RAW_LOOPBACK:
 612                 if (optlen != sizeof(ro->loopback))
 613                         return -EINVAL;
 614
 615                 if (copy_from_user(&ro->loopback, optval, optlen))
 616                         return -EFAULT;
 617
 618                 break;
 619
 620         case CAN_RAW_RECV_OWN_MSGS:
 621                 if (optlen != sizeof(ro->recv_own_msgs))
 622                         return -EINVAL;
 623
 624                 if (copy_from_user(&ro->recv_own_msgs, optval, optlen))
 625                         return -EFAULT;
 626
 627                 break;
 628
 629         case CAN_RAW_FD_FRAMES:
 630                 if (optlen != sizeof(ro->fd_frames))
 631                         return -EINVAL;
 632
 633                 if (copy_from_user(&ro->fd_frames, optval, optlen))
 634                         return -EFAULT;
 635
 636                 break;
 637
 638         case CAN_RAW_JOIN_FILTERS:
 639                 if (optlen != sizeof(ro->join_filters))
 640                         return -EINVAL;
 641
 642                 if (copy_from_user(&ro->join_filters, optval, optlen))
 643                         return -EFAULT;
 644
 645                 break;
 646
 647         default:
 648                 return -ENOPROTOOPT;
 649         }
 650         return err;
 651 }
 652
 653 static int raw_getsockopt(struct socket *sock, int level, int optname,
 654                           char __user *optval, int __user *optlen)
 655 {
 656         struct sock *sk = sock->sk;
 657         struct raw_sock *ro = raw_sk(sk);
 658         int len;
 659         void *val;
 660         int err = 0;
 661
 662         if (level != SOL_CAN_RAW)
 663                 return -EINVAL;
 664         if (get_user(len, optlen))
 665                 return -EFAULT;
 666         if (len < 0)
 667                 return -EINVAL;
 668
 669         switch (optname) {
 670
 671         case CAN_RAW_FILTER:
 672                 lock_sock(sk);
 673                 if (ro->count > 0) {
 674                         int fsize = ro->count * sizeof(struct can_filter);
 675                         if (len > fsize)
 676                                 len = fsize;
 677                         if (copy_to_user(optval, ro->filter, len))
 678                                 err = -EFAULT;
 679                 } else
 680                         len = 0;
 681                 release_sock(sk);
 682
 683                 if (!err)
 684                         err = put_user(len, optlen);
 685                 return err;
 686
 687         case CAN_RAW_ERR_FILTER:
 688                 if (len > sizeof(can_err_mask_t))
 689                         len = sizeof(can_err_mask_t);
 690                 val = &ro->err_mask;
 691                 break;
 692
 693         case CAN_RAW_LOOPBACK:
 694                 if (len > sizeof(int))
 695                         len = sizeof(int);
 696                 val = &ro->loopback;
 697                 break;
 698
 699         case CAN_RAW_RECV_OWN_MSGS:
 700                 if (len > sizeof(int))
 701                         len = sizeof(int);
 702                 val = &ro->recv_own_msgs;
 703                 break;
 704
 705         case CAN_RAW_FD_FRAMES:
 706                 if (len > sizeof(int))
 707                         len = sizeof(int);
 708                 val = &ro->fd_frames;
 709                 break;
 710
 711         case CAN_RAW_JOIN_FILTERS:
 712                 if (len > sizeof(int))
 713                         len = sizeof(int);
 714                 val = &ro->join_filters;
 715                 break;
 716
 717         default:
 718                 return -ENOPROTOOPT;
 719         }
 720
 721         if (put_user(len, optlen))
 722                 return -EFAULT;
 723         if (copy_to_user(optval, val, len))
 724                 return -EFAULT;
 725         return 0;
 726 }
 727
 728 static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
 729 {
 730         struct sock *sk = sock->sk;
 731         struct raw_sock *ro = raw_sk(sk);
 732         struct sk_buff *skb;
 733         struct net_device *dev;
 734         int ifindex;
 735         int err;
 736
 737         if (msg->msg_name) {
 738                 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
 739
 740                 if (msg->msg_namelen < sizeof(*addr))
 741                         return -EINVAL;
 742
 743                 if (addr->can_family != AF_CAN)
 744                         return -EINVAL;
 745
 746                 ifindex = addr->can_ifindex;
 747         } else
 748                 ifindex = ro->ifindex;
 749
 750         if (ro->fd_frames) {
 751                 if (unlikely(size != CANFD_MTU && size != CAN_MTU))
 752                         return -EINVAL;
 753         } else {
 754                 if (unlikely(size != CAN_MTU))
 755                         return -EINVAL;
 756         }
 757
 758         dev = dev_get_by_index(sock_net(sk), ifindex);
 759         if (!dev)
 760                 return -ENXIO;
 761
 762         skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv),
 763                                   msg->msg_flags & MSG_DONTWAIT, &err);
 764         if (!skb)
 765                 goto put_dev;
 766
 767         can_skb_reserve(skb);
 768         can_skb_prv(skb)->ifindex = dev->ifindex;
 769         can_skb_prv(skb)->skbcnt = 0;
 770
 771         err = memcpy_from_msg(skb_put(skb, size), msg, size);
 772         if (err < 0)
 773                 goto free_skb;
 774
 775         sock_tx_timestamp(sk, sk->sk_tsflags, &skb_shinfo(skb)->tx_flags);
 776
 777         skb->dev = dev;
 778         skb->sk  = sk;
 779         skb->priority = sk->sk_priority;
 780
 781         err = can_send(skb, ro->loopback);
 782
 783         dev_put(dev);
 784
 785         if (err)
 786                 goto send_failed;
 787
 788         return size;
 789
 790 free_skb:
 791         kfree_skb(skb);
 792 put_dev:
 793         dev_put(dev);
 794 send_failed:
 795         return err;
 796 }
 797
 798 static int raw_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 799                        int flags)
 800 {
 801         struct sock *sk = sock->sk;
 802         struct sk_buff *skb;
 803         int err = 0;
 804         int noblock;
 805
 806         noblock =  flags & MSG_DONTWAIT;
 807         flags   &= ~MSG_DONTWAIT;
 808
 809         skb = skb_recv_datagram(sk, flags, noblock, &err);
 810         if (!skb)
 811                 return err;
 812
 813         if (size < skb->len)
 814                 msg->msg_flags |= MSG_TRUNC;
 815         else
 816                 size = skb->len;
 817
 818         err = memcpy_to_msg(msg, skb->data, size);
 819         if (err < 0) {
 820                 skb_free_datagram(sk, skb);
 821                 return err;
 822         }
 823
 824         sock_recv_ts_and_drops(msg, sk, skb);
 825
 826         if (msg->msg_name) {
 827                 __sockaddr_check_size(sizeof(struct sockaddr_can));
 828                 msg->msg_namelen = sizeof(struct sockaddr_can);
 829                 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
 830         }
 831
 832         /* assign the flags that have been recorded in raw_rcv() */
 833         msg->msg_flags |= *(raw_flags(skb));
 834
 835         skb_free_datagram(sk, skb);
 836
 837         return size;
 838 }
 839
 840 static const struct proto_ops raw_ops = {
 841         .family        = PF_CAN,
 842         .release       = raw_release,
 843         .bind          = raw_bind,
 844         .connect       = sock_no_connect,
 845         .socketpair    = sock_no_socketpair,
 846         .accept        = sock_no_accept,
 847         .getname       = raw_getname,
 848         .poll          = datagram_poll,
 849         .ioctl         = can_ioctl,     /* use can_ioctl() from af_can.c */
 850         .listen        = sock_no_listen,
 851         .shutdown      = sock_no_shutdown,
 852         .setsockopt    = raw_setsockopt,
 853         .getsockopt    = raw_getsockopt,
 854         .sendmsg       = raw_sendmsg,
 855         .recvmsg       = raw_recvmsg,
 856         .mmap          = sock_no_mmap,
 857         .sendpage      = sock_no_sendpage,
 858 };
 859
 860 static struct proto raw_proto __read_mostly = {
 861         .name       = "CAN_RAW",
 862         .owner      = THIS_MODULE,
 863         .obj_size   = sizeof(struct raw_sock),
 864         .init       = raw_init,
 865 };
 866
 867 static const struct can_proto raw_can_proto = {
 868         .type       = SOCK_RAW,
 869         .protocol   = CAN_RAW,
 870         .ops        = &raw_ops,
 871         .prot       = &raw_proto,
 872 };
 873
 874 static __init int raw_module_init(void)
 875 {
 876         int err;
 877
 878         pr_info("can: raw protocol (rev " CAN_RAW_VERSION ")\n");
 879
 880         err = can_proto_register(&raw_can_proto);
 881         if (err < 0)
 882                 printk(KERN_ERR "can: registration of raw protocol failed\n");
 883
 884         return err;
 885 }
 886
 887 static __exit void raw_module_exit(void)
 888 {
 889         can_proto_unregister(&raw_can_proto);
 890 }
 891
 892 module_init(raw_module_init);
 893 module_exit(raw_module_exit);